1. Field of the Invention
The invention refers to a hand winch which comprises a rotating winding roll for winding up and winding off a flexible elongated member, such as a belt, a band, a cable or the like.
2. Description of the Prior Art
Typically, prior art hand winches included a rotatable rotation shaft engaged with a winding roll for transmitting manual operating forces via a crank handle connected to the shaft for rotating the winding roll. Further, specific hand winches have included an automatically activating friction brake such that the friction brake is activated automatically when a pulling load is applied to the elongated member wound up on the winding roll.
Such a known hand winch having a friction brake is disclosed in EP 2 058 266 A1. The friction brake includes a gear member mounted between the winding roll and the shaft in such a way that it can axially move along the shaft between a release position and a brake position in which it enters into friction contact with a brake disk releasably fixed to a housing of the hand winch, thereby generating friction forces that act on the gear member and thus on the winding roll and the elongated member. The fixation of the braking disk to the housing is realized by a ratchet system designed to be moved between an engaged position in which the ratchet fixes the braking disk and an off-set position in which the brake disk can freely rotate. The ratchet system functions as a mechanism for activating and deactivating the automatic capabilities of the brake system. The ratchet can be moved from the engaged position to the off-set position by movement of a pivot member of the housing of the hand winch. When a load is applied to the elongated member, the latter causes the housing element to move the ratchet into the engaged position and simultaneously the gear member entrained by the winding roll moves axially from the release position to the brake position, generating braking forces opposite the direction of unwinding the elongated member. In order to let down a load applied to the elongated member, a crank handle can be plugged into the operating shaft in order to reduce and overcome the friction forces generating the friction brake and let down the load by unwinding the elongated member.
A disadvantage of this prior art hand winch is that when the friction brake is deactivated through the brake disk being switched to the off-set position, a rapid unwinding of the belt by pulling it will result in a quick rotation of the shaft. If in this situation the crank handle is still mounted on the shaft, the crank handle will rotate with the same angular speed as the shaft, possibly resulting in injury of the operator or a bystanding person.
A further disadvantage of this hand winch shown in EP 2 058 266 A1 is that the automatic capabilities of the friction brake can only be deactivated in dependence of the position of the pivot member of the housing which causes the ratchet element to engage the brake disk or to disengage the brake disk. For an inexperienced operator of the hand winch it is not clear in which operating condition the automatic friction brake is activated and in which one it is not. Further, in order to quickly unwind the elongated member by pulling it, the elongated member must be pulled in a certain direction, corresponding to the required specific position of the pivot member of the housing of the hand winch.
It is an object of the invention to overcome these disadvantages of the prior art, in particularly to provide a hand winch including an automatic friction brake which is ergonomically improved.